Zeolite catalyst

Abstract

The present disclosure relates to the preparation of pyridine derivatives, such as α-picoline or α-parvoline, and catalysts useful for the selective preparation of such pyridine derivatives. Particularly, the present disclosure relates to the selective preparation of certain pyridine derivative using dealuminated zeolite catalysts.

What is claimed is: 
     
       1. A process for preparing a pyridine base comprising
 contacting ammonia with a C 2 -C 6  aldehyde in the presence of a metal loaded zeolite beta catalyst comprising a metal and a zeolite beta, 
 wherein the metal loaded zeolite beta catalyst is prepared by a process comprising 
 i. contacting tetraethyl orthosilicate with aqueous tertaethylammonium hydroxide to provide a silicate solution; 
 ii. contacting the silicate solution with a metal source to provide a metal-silicate solution; 
 iii. contacting the metal-silicate solution with hydrofluoric acid to provide a metal-silicate gel; and 
 iv. contacting the metal-silicate gel with dealuminated zeolite beta seeds to provide the metal loaded zeolite beta catalyst. 
 
     
     
       2. The process of  claim 1 , wherein the metal source is a Sn containing compound. 
     
     
       3. The process of  claim 1 , wherein the metal source is aqueous stannic chloride. 
     
     
       4. The process of  claim 3 , wherein the metal loaded zeolite beta catalyst has a zeolite beta topology and an absence of bulk crystalline SnO 2 . 
     
     
       5. The process of  claim 4 , wherein the tin content of the metal loaded zeolite beta catalyst is from about 1 wt % to about 4 wt %. 
     
     
       6. The process of  claim 1 , wherein the metal loaded zeolite beta catalyst comprises a metal and a dealuminated zeolite beta. 
     
     
       7. The process of  claim 6 , wherein the dealuminated zeolite beta has a SiO 2 /Al 2 O 3 molar ratio of at least about 150/1. 
     
     
       8. The process of  claim 7 , wherein the metal is in an amount of less than about 10% by weight compared to the metal loaded zeolite beta catalyst. 
     
     
       9. The process of  claim 8 , wherein the metal selected from the group consisting of Sn, Ti, Mn, Fe, Co, Zn, and combinations thereof. 
     
     
       10. A process for preparing a pyridine base comprising
 contacting ammonia with a C 2 -C 6  aldehyde in the presence of a metal loaded zeolite beta catalyst comprising a metal and a zeolite beta, 
 wherein the metal loaded zeolite beta catalyst is prepared by a process comprising
 contacting a dealuminated zeolite beta with a metal source to provide the metal loaded zeolite beta catalyst. 
 
 
     
     
       11. The process of  claim 10 , wherein the dealuminated zeolite beta is provided by
 contacting a zeolite beta catalyst having a SiO 2 /Al 2 O 3 molar ratio of about 15 to about 90 with a mineral acid. 
 
     
     
       12. The process of  claim 11 , wherein the mineral acid is selected from the group consisting of nitric acid, hydrochloric acid and phosphoric acid. 
     
     
       13. The process of  claim 1 , wherein the metal loaded zeolite beta catalyst is mixed and formed with a binder selected from the group consisting of SiO 2 , Al 2 O 3 , kaolin, montmorillonite, and titania to provide a metal loaded zeolite beta catalyst composition. 
     
     
       14. The process of  claim 1 , wherein the C 2 -C 6  aldehyde is selected from the group consisting of acetaldehyde, propionaldehyde, crotonaldehyde and butyraldehyde. 
     
     
       15. The process of  claim 1 , further comprising
 regenerating the metal loaded zeolite beta catalyst remaining after step of contacting ammonia with a C 2 -C 6  aldehyde by contacting the metal loaded zeolite beta catalyst with air at a temperature of from about 500° C. to about 600° C. 
 
     
     
       16. The process of  claim 15 , further comprising contacting ammonia with a C 2 -C 6  aldehyde in the presence of the metal loaded zeolite beta catalyst obtained from the step of regenerating the metal loaded zeolite beta catalyst. 
     
     
       17. The process of  claim 1 , wherein the pyridine base is α-picoline. 
     
     
       18. The process of  claim 1  wherein the pyridine base is α-picoline and the α-picoline is formed in a ratio of at least about 2.5:1 of a-picoline to y-picoline side-product. 
     
     
       19. The process of  claim 1 , wherein the pyridine base is α-parvoline. 
     
     
       20. The process of  claim 10 , wherein the metal source is SnO 2 , SnCl 2 , SnSO 4 , or Sn(CH 3 CO 2 ) 2 .